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Refrigerant-transporting hose

a technology for refrigerant and hose, which is applied in the direction of transportation and packaging, mechanical equipment, other domestic objects, etc., can solve the problems of poor adhesion between the two layers and the inability to directly bond the layers, and achieve excellent acid resistance properties, excellent bend resistance properties, and prevent the effect of hose cracking

Active Publication Date: 2014-06-03
SUMITOMO RIKO CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0007]That is, the present inventors have intensively researched focusing on an inner layer in contact with a fluorine refrigerant in order to obtain a refrigerant-transporting hose (excellent in bend resistance property) that can prevent cracking of the hose while having excellent acid resistance property and excellent interlayer adhesiveness without using an adhesive. In course of the research, the present inventors focused on polypropylene that has better acid resistance property than polyamide resin, and came up with an idea of forming a layer (innermost layer) made of polypropylene on an inner periphery surface of a layer made of polyamide resin. However, adhesiveness between the both layers is poor; therefore the both layers could not be directly bonded without an adhesive (free of adhesive). Then, as a result of further experiments, the present inventors found that the use of maleic anhydride-modified polypropylene obtained by modifying polypropylene with maleic anhydride can realize a direct bond between an inner layer including maleic anhydride-modified polypropylene as a main component and an intermediate layer including polyamide resin as a main component without an adhesive (free of adhesive) and results in excellent bend resistance property, and completed the present invention.
[0008]As described above, the tubular inner layer in contact with a fluorine refrigerant of the refrigerant-transporting hose according to the present invention is made of an inner layer material including maleic anhydride-modified polypropylene as a main component. Thus, the inner layer is excellent in interlayer adhesiveness with the intermediate layer made of an intermediate layer material including polyamide resin as a main component. The both layers can be directly bonded with each other without an adhesive (free of adhesive). In addition, the tubular inner layer in contact with a fluorine refrigerant includes as a main component polypropylene with excellence in acid resistance property. Accordingly, even if acid is generated due to degradation of a fluorine refrigerant, infiltration of the acid into the intermediate layer including polyamide resin as a main component can be suppressed. The refrigerant-transporting hose according to the present invention therefore can prevent cracking of the hose due to decomposition of an amide bond and is excellent in bend resistance property.
[0009]In addition, if the modification amount of the maleic anhydride-modified polypropylene is 0.26 to 0.36 weight %, interlayer adhesiveness and bend resistance property of the refrigerant-transporting hose according to the present invention are further improved.
[0010]Further, if the melting point of the maleic anhydride-modified polypropylene is 165 to 168° C., interlayer adhesiveness and bend resistance property of the refrigerant-transporting hose according to the present invention are still further improved.
[0011]Then, when the rubber layer is a butyl rubber layer, water blocking property (water barrier property) of the refrigerant-transporting hose according to the present invention is further improved.
[0012]In addition, when the rubber layer is an ethylene-propylene rubber layer, heat resistance property of the refrigerant-transporting hose according to the present invention is further improved.

Problems solved by technology

However, adhesiveness between the both layers is poor; therefore the both layers could not be directly bonded without an adhesive (free of adhesive).

Method used

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  • Refrigerant-transporting hose
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  • Refrigerant-transporting hose

Examples

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examples

[0059]Next, examples will be described together with a comparative example. However, the present invention is not limited to these examples.

[0060]Prior to describing the examples and the comparative example, an inner layer material and an intermediate layer material described below were prepared.

[Maleic Anhydride-Modified Polypropylene (for Example)]

[0061]ADMER QF500, manufactured by Mitsui Chemicals, Inc. (modification amount 0.27 weight %, melting point 165° C.)

[0062]ADMER QF551, manufactured by Mitsui Chemicals, Inc. (modification amount 0.36 weight %, melting point 135° C.)

[0063]ADMER QB510, manufactured by Mitsui Chemicals, Inc. (modification amount 0.28 weight %, melting point 160° C.)

[0064]MODIC P-502, manufactured by Mitsubishi Chemical Corporation (modification amount 0.26 weight %, melting point 168° C.)

[Unmodified Polypropylene (for Comparative Example)]

[0065]Unmodified PP [FS2011C, manufactured by Sumitomo Chemical Co., Ltd. (melting point 170° C.)]

[Polyamide Resin]

[0066...

examples 1 to 6

[0071]A hose was made by using an inner layer material, an intermediate layer material, and a rubber composition (a inner rubber layer material and a outer rubber layer material) shown in Table 1 below. That is, the inner layer material and the intermediate layer material were extruded on a mandrel (outer diameter 12 mm) made of TPX (manufactured by Mitsui Chemicals, Inc.) in a hose-like shape to form an intermediate layer on an outer periphery surface of an inner layer. Next, the inner rubber layer material was extruded on an outer periphery surface of the intermediate layer to form an inner rubber layer. Subsequently, a reinforcement layer was formed on an outer periphery surface thereof by braid weaving of a PET thread. Further, the outer rubber layer material was extruded on an outer periphery surface of the reinforcement layer to form an outer rubber layer. Then, this was vulcanized (170° C.×30 minutes). Subsequently, a hose (inner diameter 12.0 mm), in which an inner layer (th...

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Abstract

A refrigerant-transporting hose includes a tubular inner layer 1 in contact with a fluorine refrigerant, an intermediate layer 2 formed on an outer periphery surface thereof, and at least one rubber layer 3 and 5 formed on a further outer periphery thereof, and the inner layer 1 is made of a inner layer material including maleic anhydride-modified polypropylene as a main component and the intermediate layer 2 is made of a intermediate layer material including polyamide resin as a main component.

Description

TECHNICAL FIELD[0001]The present invention relates to a refrigerant-transporting hose such as an air conditioner hose. More particularly, the present invention relates to a refrigerant-transporting hose that can transport a fluorine refrigerant such as Freon (R12) and alternative Freon (for example, a single refrigerant R-134a and a mixed refrigerant Fluid H) and is used as a piping hose in an automobile engine room and the like.BACKGROUND OF THE INVENTION[0002]Generally, in a refrigerant-transporting hose used as a piping hose in an automobile engine room, a fluorine refrigerant such as Freon (R12) and alternative Freon (such as R-134a) is used. In recent years, since the regulation on transpiration of ozone layer depleting gas is tightened, requirements on refrigerant permeability of a refrigerant hose for an automobile have become strict; therefore, resin having high crystallinity such as polyamide resin is used as a material for an inner layer of a refrigerant-transporting hose....

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): F16L11/00
CPCF16L11/085F16L2011/047B60H1/00571F16L11/04B32B1/08B32B25/08B32B25/18B32B2597/00Y10T428/1393
Inventor OYAIZU, NAOKIKATAYAMA, KAZUTAKATAGUCHI, TAKEHIKOMORI, HIROYOSHIDAIKAI, EIICHIWAKAZONO, YUKINORI
Owner SUMITOMO RIKO CO LTD